Tabs cannot be rearranged. Tab drags with mouse, but space remains, and tabs don't shuffle over to make room. Placement arrow does not appear. When released, the tab pops to the vacant spot it came from. Problem appeared when Firefox updated to 49. Same on two different computers running Vista and Windows 7. If I disable either tab Mix Plus, OR Multiple Tab Handler, the tabs drag normally. (Both worked together previously, for years). I made no changes in the option settings on either computer. I did not install any new add-ons. It might have been 49.0.1 when it first 'broke', and is still same with 49.0.2. I never had the shift-click and ctrl-click configured as recommended; but I tried that too and it did not help. (I had them set for MTH to control, now I have them set as recommended with TMP controlling selections). Has anyone else using both these extensions encountered this? Should I report this to the author(s)? Or somewhere else? This is my first post, is it in the right/best place? Thank you, Mr KL